BIOC37: Midterm

Reproduction

Reproduction

The biological process by which plants produce offspring, involving various strategies such as semelparity, biennial, and perennial systems.

Sedentariness

Crux of being a plant. It needs to be able to manipulate the environment

Semelparous plants

Plants that reproduce only once in their lifetime, germinating and investing in growth before dying after reproduction. Dire to reproduce.

Biennial plants

Plants that live for two years, producing leaves in the first year and flowering in the second year after storing nutrients.

Perennial plants

Many growing seasons. Guy hangs around every year, never flowering, builds carbon blocks/reserves for years and produces the giant inflorescence and then dies.

Iteroparous plants

Plants that reproduce repeatedly throughout their lifespan, such as trees. Produce multiple times a year. Two experimental fields of white clover grow way worse with inbreeding. How do they maximize the quality?

Inbreeding depression

The reduced biological fitness that can result from mating between closely related individuals, as seen in white clover.

Female quality control

Mechanisms by which female plants select for high-quality pollen to ensure better offspring.

Style competition

The process where multiple pollen grains compete to fertilize ovules, influencing offspring quality. Female wants many pollen grains to land and compete so only the fastest growing will pollinate the egg cells. Faster it grows, more likely to have good genes. Stigma is the top, style is the middle tube section, and the ovary (few eggs) are at the bottom of the track.

Style evolution

Increasing accommodation for race. Primitive angiosperm had enough space for pollen tubes, stigma was shorter, multiple tracks to ovaries. In more modern/advanced angiosperm, it has a bigger stigma, one tunnel connecting stigmatic surface to one ovary (higher competition)

Nectar

A high-energy food reward produced by plants to attract pollinators, crucial for mutualistic relationships. Adult worker bees primarily, also butterflies and hawk moth. Produced in nectaries. Insects have to work hard to get access to these nectaries. Holes look like stomata, but are glands that use the nectar. They got much deeper as time went on.

Nectar spur

Located at very base of flower, gotta pass through a bunch to get your hit. Hollow organ that secretes nectar in some flowers.

Nectar primary compounds

Energy pollinators are after this. Made up of sucrose, glucose, and fructose

Nectar secondary compounds

Toxins keep unsuitable species out (nectar robbers, microbes) or invite in others. Toxins, smells, tastes, or attractants making them irresistable.

Sucrose composition / Sugar concentration

Bats: Low sucrose, low sugar concentration

Lepidoptera: High sucrose, high concentration (viscous, very fragrant)

Hummingbirds: High sucrose, low concentration

Pollen

The male gametophyte of seed plants, rich in protein and essential for fertilization. Consumed by juveniles. Collected on the body of the bees, hind legs, pollen baskets on outside of hind leg, and pollen press (front of joint).

Anthers

Typically pop out colour-wise in comparison to petals, the pollinating ones are inconspicuous, the pollen from conspicuous ones is wasted in terms of flower fertilization. Feeding and pollinating ones (cryptic)

Resin

A sticky substance produced by some plants that can deter pests and provide structural support for nests built by certain bees. Resin ring. Sticky, hydrophobic, bees collect. Collected by some lone female bees.

Resin uses

Contains chemical properties (antifungal, antibacterial), reduces risk of disease and parasite transmission in brood chambers, collected by solitary female bees.

Increases structural nest stability, and defense (sealing).

Fragrance

Lots of flowers smell good to attract, and some species collect it. Scent collection by some male bees.

Female euglossine bees prefer fragrant males. Males go collect this (and inadvertently pollinate flowers. Bees scrape off smelly oil, get the sticky oil smell of orchids in hind legs (oil container)).

Nectar robbing

A behavior where pollinators access nectar without providing pollination services, negatively impacting plant reproduction.

Hammer head orchid

Fake female wasp (head, torso, fur). Hinge between female dummy and rest of flower. Pollen packages (pollinia). Male wasps at half their fertility when they’re around. The male will attack, get glued and will bump against the pollen trying to escape. It will fly around with the pollen packages. Uses a very potent fake scent. 10x pheromone.

Attractiveness of Andrena bees

Female ophrys flower > extract of flower > female bee with smell > female bee without smell

Jack-in-the-pulpit

Some cheating flowers are traps. Deceptive fungus-scented smell. Outer structure (pulpit), inner structure (jack). Jack produces a pheromone that smells like a fungus. Mamas want to lay eggs there. Purely male and female plants. Jack in the pulpit need to make their pollen flown over to females.

Angiosperm diversification

Angiosperms started diversifying in cretaceous. Angiosperms youngest and most diverse. Radiation of many insect groups. The radiation of flies and bees occured in parallel to the evolution of angiosperms.

Bat

White, green, or purple. No nectar guides. Abundant nectar, hidden. Strong and musty odor emitted at night. Ample pollen. Bowl shaped, closed during the day.

Bee

Bright white, yellow, blue, or UV. Nectar guides. Fresh, mild odor. Usually has nectar. Limited in pollen, sticky and scented. Shallow with landing platform, tubular.

Bird

Scarlet, orange, red or white (prefer red). No nectar guide. No odor. Ample necter, deeply hidden. Limited pollen. Large, funnel-like shape, strong perch support.

Butterfly

Bright red and purple (prefer red). Nectar guides. Faint, fresh odor. Ample, deeply hidden nectar. Limited pollen. Narrow tube with spur, wide landing pad.

Moth

Pale red, purple, pink or white. Strong, sweet smell emitted at night. Ample, deeply hidden. Limited pollen. Regular, tubular, without a lip shape.

Dalenchampia flowers

Exclusively pollinated by bees. Different bees which collect different rewards. Switch between pollinators has happened many times evolutionally. 48 species. Even though we think of systems being specific, mutation alone, results in a switch in pollination system.

Pollination syndromes

Adaptations in flowers that attract specific pollinators, enhancing reproductive success.

Abiotic pollination

Pollination that occurs without the involvement of animals, often through wind or water. Wind is in 10% of flowering plants, and 18% of all families of flowering plants have a wind-pollinated species.

Mallows

Special stigma and anther modification for fertilization. The anthers are inserted in close proximity to the stigma, allowing for selfing as a last resort when pollinators have not visited during most of the fertile period of the stigma.

Generalist pollination

less risk of failure. Easier to colonize new areas. Generalists colonize new areas better.

Average nectar concentration. Many flowers from large landing platform for any insect. Elderberry, goldenrod, Queen Anne’s lace. Coltsfoot. Tiny flowers, landing platform.

Monecious plants

Plants produce 2 types of flowers. Both sexes on same plant but nor same flower. M, F. 17%.

Dioecy

6% of angiosperms. Plants each have one sex, populations have two sex. Risky way of reproduction. Allows unisexual flowers to fully specialize on needs and gender potential. 100% outcrossing. 100% specialization on M or F needs. Selfing is possible for all plants except this kind.

Gymnomonoecy

a M+F flower, and a female only flower

Andromonoecy

M+F flower, and a male only flower.

Gynodioecy

Female only plant, M+F only plant.

Androdioecy

Male only plant, M+F only plant

Hermaphroditism

75% of angiosperms. Less risky. Anthers rub on stigma. Sexual conflict in terms of advertising. Mechanical issues and inbreeding depression through selfing. M+F on a flower.

Early-acting SI

Pollen from own genes. Compatible pollen, entering straight, while rejected pollen is curled and plugging stigmatic surface

Intermediated acting SI

Tissue of female structure recognizes genes of pollen, stopping tube growth two avoid selfing. Stylar plugging around incompatible pollen tubes (curling). Recognized by tissue.

Late-acting SI

Pollen grows all the way, ovule recognizes pollen tube, doesn’t fertilize.

Spatial separation

Sexes are active at the same time, but organs are too far from each other, and there is a low chance of pollen every tom make it into (a next individuals stigma).

Issue with hermaphroditic flowers being on same flower. Partial overlap of sex inflorescence can be another issue.

Temporal separation

M-phase closed, F phase open. Either can come first.

Issue with monoecy, where simultaneous flowering of M & F in one inflorescence. Partial overlap of sex inflorescence can be another issue.

M phase

anthers straight, just opened, stigma not active, physical/temporal distance.

Fitness: 1000s of pollen, many visits necessary to empty anthers. Biggest 70% of the time. Easier to see, lures pollinators to come pick up pollen. Smell more. More nectar (4x) as an incentive to pollinators.

F phase

Anthers empty, older flower, styles longer/F more optimized.

Fitness: 1 to hundreds of eggs. One or few visits necessary for full seed sets. Biggest 25% of the time. Cut cost on odor to make egg bigger. Less nectar.

Mycorrhizae

Symbiotic associations between fungi and plant roots that enhance nutrient uptake, particularly phosphorus.

Cluster roots

Specialized root structures that enhance phosphorus uptake in nutrient-poor soils. Steroids. Huge. Occur like beads on a string. Way more carbon building blocks. Minerals and phosphorus. Very common in old soils. Complex and Simple.

Plant. Phosphorus limited soil. ? species.

Carnivory

Changed leaf morphology to go after N. Plants, young leaf does photosynthesis, it will grow to ever increasing size, until functional. Pointy end of leaf. Traps are mostly after nitrogen.

Plant-animal interaction. Nitrogen poor soil. Less than <1000 sp.

Parasitism

A relationship where one organism benefits at the expense of another, with types including hemiparasitism and holoparasitism.

Plant-plant interaction. Many to all limited. 4000 sp.

Desiccation tolerance

This is uncommon in angiosperms (they can’t survive losing all their water), all have been able to avoid complete loss of seeds. Mouses are the champions of surviving all water loss. Tissues resume photosynthesis and they can survive. Real issue, is most groups, except for mosses. Mosses can’t dehydrate.

Problems from desiccation

Mechanical damage due to shrinkage. Disintegration of membranes. Aggregation of macromolecules while shrinking. Disintegration of PS apparatus. Accumulation of UV-induced damage while dry.

Solution for desiccation

Sugars (trelahose) takes place of water molecules. No aggregation of macromolecules and no disintegration of membranes as cells dry. Stabilization of drying cells. Mostly trehalose taking place of water molecules. Any structures propped up by water, were propped up by trehalose. One protein, another protein. Proteins are set apart by water molecules. Plants will stick on trehalose, occupying the same space as the cell.

Drought-deciduous perennials

During wet times, plant has leaves. As it is exposed to high heat and low water. It can’t keep up and drops all leaves. Hibernation, adult structure abover ground. Comes back to PS life when enough water again.Leaves can’t retain H₂O. Drop them, regrow them after the next train.

Sclerophylly

The development of tough, thick leaves in plants as an adaptation to arid environments. Dead at maturity, cell interior almost completely filled. Cell walls thickened with cellulose and usually strengthened with lignin.

Ocotillo

Once water is going, it’ll toss the leaves, maintain water in roots and stems. Stomata in leaves, so without them, they can’t lose water really. In flower, dropped leaves. Drop and regrow on multiple occasions through the year.

Boundary layers

Decides dissipation of heat. Dissection size correlates to this correlates to dissipation of heat.

Further away from leaf → more heat stuck near and in leaf (less dissipation). Closer to leaf, smaller boundary layer, ridges and small leaf → less heat stuck near and in leaf (more dissipation).

Lupid

Can't take low concentrations of salt, max 100% with no salt. Barley can deal with some level of salt. Salt bush is a real halophyte, can deal with a ton

Life history seed size

Non-wood annual herbs < non-woody perennial herbs < woody shrubs < woody trees

Escape hypothesis

The more seeds are present, the more likely they are to die. Reasons why they’re more likely to die is because organisms who like to feed pull up and kill them all. Predators and resource limitation. Common.

Colonization hypothesis

Chance for offspring to occupy unpredictably good sites. Successional communities (ecosystems in change). Typical for r-selected species (disturbed sites, weeds).

Trees which produce cheapest trees. Tiny, hairs, travel far, they produce so many seeds to hit anywhere. Very few establish. Cottonwood, trembling aspen. Common.

Directed seed dispersal

Non-random reach for a particular, predictably suitable places for establishment and growth. Good sites are more stable and plant can get seed to good sites. Ants carry seed. Rare.

Anemochory

Wind-dispersed. Hairs are feathery, common-milkweed. Wings (birches). Tiny, winged, orchid seeds. Poppy. Tumbleweeds. As it hits the ground. seeds fall off the plant. 100 m distance.

Hydrochory

Hard seed case, airpocket to float. You can find them near tropics and the sea. Their hard coats stay intact in the abrasive sea for a long time. Common along big tropical rivers (amazon). Trees along seashores. Coco de mer (world’s largest seed) - surprisingly light and only one embryo. Long-lived embryo. 100s-1000s of km.

Splash seed dispersal

perfect angle of open ovary walls to harvest maximum impact of raindrop. Energy of raindrop will catapault seeds away. less than 1m.

Myrmecochory

Forest spring flowers in ON rely heavily on this. Where ants collect seed with elaiosome. Ant pick up seed and shove back into nest. Feed to offspring. Elaiosomes only get removed from seeds inside the ant colony, fed to larvae. 10-80m away.

Exozoochory

Hooks and barbs of seeds. Catches onto clothing. Grow to animal size. 50 m.

Evil exozoochory

Seeds located inside the pod, hole where ripe seeds are dispersed, sticks in things. Gets really attached to a shoe or foot. Low key dangerous.

Endozoochory

Birds have no teeth, but adapted stomachs. Grinds and digests the seeds. Gizzard stomach. Birds swallow pebbles to digest food. Thick seed coat to survive. Will not germinate until after it has migrated through gizzard. Gets scarified. Up to 100s km in geese.

Barochory

Big, fatty seeds. Great winter food. Seeds fall from plant when ripe. Seeds are picked up by animals and dispersed. Scatter hoarding. Falls to ground and some move less than 5 meters away. Only few are taken very far away. Lots of herbs and seeds disperse not very far.

Ballistochorous

Falls to ground and some move less than 8 meters away. Only few are taken very far away. Lots of herbs and seeds disperse not very far. Shot.

Fire dispersal

Seed dormancy, highly nutrient-poor soils and fire-prone habitat. Serotinous cones. Jack pine.

Long distance dispersal

Depending on how they got there, they could come back or no. Average max dispersal is 30m a year. How far did american ginger travel with help from ants? 23m a year - 10 km in 16000 years. Major hurricane - 80km. Ontario is 33% invasive species.

Seed dormancy

suspension of the embryo. Mature seed doesn’t germinate right away (waiting for a time period). Lag time between when it is mature and starts to grow. When drought period is over, or there is more resources, or less competition. Break by change in light, embryo maturation, stomach acid, plant hormone, smoke.

Phosphorus cycle

bedrock → weathering → soils → living organisms

Nitrogen cycle

obligate organisms - there is no life as we know it on earth without them (red). Facultative helpers (green)

Taking up cations

The carbon dioxide in the soil solution from the plant reacts with water to produce bicarbonate and a hydrogen proton. The hydrogen protons are then exchanged for cations on soil particles allowing the plant to absorb the now dissolved cations.

Cation exchange capacity CEC of soils

Clay and humus are dead and organic matter. Negatively charged sites - surrounded by water. H+ strongest affinity to negatively charged soil sites. Plant roots can only take up dissolved minerals (in soil solutions)

Arbuscular mycorrhizae (AM)

obligate symbiont → limited saprophytic ability (dependent on plant C). On average, 6% of plant’s C to AM fungus. 6x better P uptake into AM that plant root (N, H₂O). No visible fruiting bodies - subterranean spores. AM fungi really bad at working with dead material, and it totally relying on plant carbon. Gets 6x better phosphorus uptake. Comparison of tiny root hair. When you see mushroom is it not AM fungi - they are in the soil, reproduce in soil space. Hyphae increase surface area.

Very simple. Endophytic.

Ectomycorrhizae (EM)

10% of plant families have this. between and outside cells of the cortex. Located outside and inbetween the root hairs. A lot of our species have ectomycorrhizae. Working in: Fungal sheet, cortex (with hartig net between), endodermis in the middle. Hyphae increase surface area, wall-degrading enzymes and protease to help access organic N and P. LARGEST. Balanced.

Ericoid mycorrhizae (ErM)

Growing with plant order Ericales. Common peat bog plants. Epidermis with root hairs → Only one cell layer deep. Mycorrhiza is inside. In one cell layer, it can grow inside like EM. Fungi secretes protease and phosphates, plant wall degrade and pheno-oxidizing enzymes. SMALLEST. Exploitative.

Altitudinal, latitudinal gradient

Bryophytes

Majority have a specific mycorrhizae, otherwise the predominant is AM. Uneven distribution of mycorrhizae. We have arbuscular. What is happening inside angiosperms. We have three main groups.

Monocots

main, big group. Similar to lower vascular plants, the predominant is AM. Differ from core eudicots and rosids

Leguminous root

Rhizobium can be found in nodules on these

Gunnera and Nostoc

cyanobacteria. Cross section of stem in a gunnera. Nostoc bacteria lives in the stem base.

Alder trees and Frankia

Alder lives close to running water, habitats tend to have nitrogen washed out. Ecosystems close by are nitrogen depleted. Alder trees symbiotic with frankia, allowing it to live in nitrogen depleted environment.

Bayberry and Frankia

Bayberry is a shrub in gravel and sand. Barberry colonizes these areas with Frankia on its tail. It becomes more and more closed. As now soils are more enriched in nitrogen.

Legume + Rhizobium

Leaving behind completely new soils. Lupens belonged to the legume family, have rhizobium, enriching soil in this area post disaster. First wave able to survive N-devoid volcanic soil

Rhizobial infection

It starts outside of cross section. Freeliving rhizobium are attracted to leach carbon from root hair (they're nearby by chance). Curl and it continued to grow. Infection thread in infected root hair. Grow through hair and into the cortex. Heavily divide. Evermore. Root nodule where rhizobia bacteria start to divide. Vascular tissue, move stuff into. Infected thread curls.

Pitfall traps

Lid → insects crawls in → gets stuck in water or something at the bottom → lid close. Passive. Container with digestive juices. Transparent windows. Slippery rim, teeth, hairs, lid. Has digestive juices. Genera over time broke down, building blocks taken up.

Flypaper traps

Surface area of leaves have nectar looking glue. Droplets or whatever else are sticky. Sundew - sticky glands, look like nectar. Glands will grow to fly. Big exposer.

Snap traps

Venus fly trap. Closes when it feels the movement. Both sides have 3 trigger hairs each. Insect lands, nectar involved. If they touch trigger hairs twice in 30 seconds, it’s not just wind and the trap closes. As moving inside, trap closes more and more

Suction traps

Bladderwort is a plant that is helped to float. Structures, actual traps, catching zooplankton. Microscopic traps. Tiny suction plants where three hairs when touched, will release trap.

Shoot parasitism

Mistletoe: Hemiparasite, still green. Seeds are sticky, glue to branch. Tend to roost in trees. Can have multiple mistletoe species on them.

Dodder: Holoparasite. No connection to root. Grow on trees. Giant mess of spaghetti. Daughter outcompeting on light access. Double on the one hand. Losing access to light.

Root parasitism

Establish connection with host via the root. Smallest class of parasite - internal parasitism - inside roots. May see only slightly above ground. Beach drops.

Internal parasitism

Raffesia, root parasite. Produce soccer ball sized buds. World’s largest flower. Mostly spends time in the roots itself.